Apparatus for washing and cooling gases



0m. 18, 1%49 QULKOSKY APPARATUS FOR WASHING AND COOLING GASES 2Sheets-Sheet 2 Filed Aug. 4, 1945 Patented Oct. 18, 1949 APPARATUS FORWASHING AND COOLING GASES Martin Culkosky, Gary, Ind.

Application August 4, 1945, Serial No. 608,907

3 Claims. (Cl. 261-11) This invention relates to an apparatus forwashing and cooling gas, particularly compressed gas as it leaves thecompressor.

An object of the invention is the provision of cheap, easily made andmaintained apparatus for removing oil, dust, and other foreign materialsfrom compressed gas and for cooling the gas so as to insure gas freefrom excess moisture during its travel to the point at which it is used.

This and other objects of the invention will be more fully apparent inthe following description.

In installation in which gases are compressed, for instance compressedair systems, considerable trouble has been encountered due to foreignmaterials in the compressed gas, such as dust particles, entrainedmoisture. and oil which may be introduced into the gas by thecompressor. In an attempt to eliminate the first two of such materialsfrom the compressed gas there have been used air filters and moistureeliminators which have been installed in the air intake between theatmosphere and the air compressor. Such devices, however, obviously donot eliminate the oil which may be introduced into the air by thecompressor, nor do they, eliminate the excess moisture in the compressedair caused by its reduction in volume and elevation'in temperature dueto compression and its cooling in the main on the way to its point ofuse. As a result of such heating and subsequent cooling in the main,excess moisture in such prior installations has been deposited in themain and branch distributing pipes and has caused dimculty in theapparatus in which the compressed air is used.

The present invention provides a simple apparatus whereby compressedgases, particularly at a point immediately following the compressor,

may be substantially freed from such foreign materials as dust, oil, andexcess moisture, and may be cooled to such a temperature and have itsmoisture content so adjusted that the gas will be saturated withmoisture at the pressure and temperatureat which it is distributed andused.

The invention will be more readily understood by reference to theaccompanying drawings, in

Figure 3 is a view in vertical cross section through such gas washer andcooler, the section being taken along the line III1'J1 in Figure 2;

Figure 4 is a view in a horizontal cross section through the apparatusshown in Figure 3, the section being taken along line IV-IV of thatfigure; and

Figure 5 is a view in vertical cross section through the-trap connectedto the gas washer and cooler for the elimination of the foam and excesswater from the cooling water bath thereof.

In the apparatus shown in Figure 1 the gas compressing, washing,cooling, distributing, and utilizing system consists generally of a gascompressor 3 which may be of any known type, such as a rotary orreciprocating compressor, which feeds the compressed gas through thepipe 6 into the gas washing and cooling apparatus generally designatedby the reference character I. From such washing and cooling apparatusthe gas now cleaned and cooled and with its moisture content adjusted asabove described, is led through pipe 26 into the compressed gasdistributing main 1 from which it may be taken at various desiredpoints, as by a branch pipe 9 tapped thereinto, to the various pieces ofapparatus employing compressed gas, of which in the case of compressedair the air driven abrading device II is typical. The air compressor 3is shown provided with a filter 5 between the intake and the atmosphere;it is preferred that such be employed to minimize wear on the compressorby dust particles in the air and to reduce the amount of impurities tobe removed by the air washer and cooler. It is possible, however, by useof such air washer and cooler l as shown to dispense, if desired, withthe intake filter on the compressor.

The gas washer and cooler l consists of a fluid tight tank 2, which isshown of generally cylindrical shape, having a central axially directedright circular cylindrical downcomer 4 projecting through the topthereof, said downcomer being closed at the top but being open at thebottom at a point well below the top of the bath of liquid gas washingand cooling medium maintained in the tank. The compressed air inlet pipe6 leads into the top of the downcomer, as shown in Figures 1 and 3, andis provided on its inner end with a nozzle 8 directed downwardly andgenerally tangentially to the inner surface of the downcomer, as shownin Figures 2 and 3. A further pipe [0, for the introduction of purgingsteam when the apparatus is to be cleaned, leads into the top of thedowncomer at a point opposite to that at which pipe 6 enters, pipe lbeing provided on its inner end within the downcomer with a nozzle 12likewise directed downwardly and tangentially of the inner surface ofthe downcomer. During normal use of the apparatus in washing and coolinggas steam is not admitted through pipe I and nozzle H, the shut-01f inpipe l0 being closed.

The lower open end of the downcomer is positioned axially of the tank bymeans of a periorated plate l4 extending transversely of the axis of thetank. Plate l4 may be positioned and secured as by being welded to thedowncomer, the tank, or both. In its normal operative condition the tankis provided with a bath of not be renewed until the next cooler andwasher cleaning operation. Such bath may be intro-- duced as by removingthe plug in top hole 34 and connecting a liquid supply pipe such as ahose thereto. The provision of a plurality of openings 34 makes possiblethe employment of different levels of the liquid bath in the tank toinsure eincient operation under varying conditions, such as varyingpressures to which the gas is compressed.

The gas washer and cooler of the present invention thus far describedfunctions as follows:

cooling liquid, as for instance water, which when the apparatus operatesas shown extends to the height of the line IE within the tank outsidethe downcomer but i depressed to a level H3, in the same horizontalplane as the lower edge of the downcomer, due to the pressure of theincoming compressed gas. Such gas after traveling downwardly through thedowncomer, escapes from the lower end of the downcomer and then passesupwardly through the perforations in plate l4 into the space within thetank outside the downcomer and above the liquid bath whence it is led tothe compressed gas main by pipe 26. The inner end of the pipe 26 extendsinwardly some distance from the inner wall of the tank to prevent thecondensate which flows down the inner wall of the tank from entering thepipe. Positioned below plate 14 is a cooling coil supplied withrefrigerant by inlet and outlet pipes 22 and 24, respectively, so thatthe washing and cooling bath may be maintained at a constanttemperature. Some means of cooling the bath, such as the cooling coilshown, is necessary if the apparatus is to be operated for anyappreciable time, since the gas leaving the compressor is at atemperature well above normal atmospheric temperature due to itscompression.

A further steam pipe is led to the bottom of the tank at a pointimmediately above plate l4, pipe 30 being provided at its inner end witha nozzle 32 directed downwardly and tangentially of the wall of the tankas shown in Figures 3 and 4. The shut-off shown in pipe 30, as is thatin pipe l0 above described, is normally closed, purging steam beingintroduced within the tank only during the infrequent periods in whichthe liquid bath is removed and the tank is cleaned. When the tank iscleaned the shut-off in blow-off pipe 28 at the bottom of the tank isopened to run the liquid bath out of the tank and to allow the exhaustof sludge and steam during the purging operation.

Along one side of the tank there is provided a series of openings 34lying vertically one above the other. During normal operation of theapparatus but two of the openings are used, the others being closed byplugs screwed thereinto. In the lower of the openings utilized there isscrewed a pipe 38 leading to the foam and excess water eliminating trap40, and in the opening thereabove there is screwed the water leveldetermining pipe 36. Trap 40, which will be more fully describedhereinafter, functions to maintain the level I 6 of the bath constant aswell as to remove foam from the top of the bath. It is preferred,-however, occasionally to try the level of the bath by opening theshut-off in pipe 36 to make sure the water level has not risen too highfor emcient operation. When once introduced and brought to the properheight, the liquid bath need The gas, heated by reason of itscompression, and containing entrained moisture, oil, and some dustparticles, enters the downcomer through the .nozzle 8 in the directionshown by the arrows. By

reason of the direction of nozzle 8 tangential to the wall of thedowncomer the gas, traveling at high velocity, impinges at a substantialangle upon the wall of the downcomer, thereby tending to depositentrained particles of solid matter as well as .oil and water on theinner surface of the downcomer. The oil and water then trickle down intothe washing and cooling bath, carrying with it any deposited solidparticles. The gas then continues its travel down the downcomer in aspiral direction until it emerges from the lower end of the downcomerand enters the liquid bath. The gas then travels upwardly at a greatlyreduced velocity through theperforated plate l4. The plate l4 causes theair to be divided into a plurality of fine streams and bubbles andconsequently to be intimately contacted by the liquid bath so that it isefficiently cooled and thoroughly cleaned. In the preferred mode ofoperation of the device the cooling coils 20 are kept to suchtemperature relative to the volume of the liquid bath and of the gastraveling therethrough that the gas entering pipe 26 is at a temperatureequal to the coldest temperature encountered by it in its travel to itspoint of application; the gas entering pipe 26 will obviously be at ornear saturation, due to its travel through and intimate contact with thecooling liquid. Consequently in its travel through the gas main 1, thebranch pipe 9, and in the gas utilizing apparatus such gas does notdeposit moisture.

The solid particles removed from the compressed gas, as well as the oiland water removed therefrom, pass down the inner surface of thedowncomer and into the washing and cooling liquid bath. To remove theexcess water so added to the bath, and thus to keep the bath levelconstant, as well as to remove the oil, which forms a foam on top of thebath, and such solid particles as are caught therein rather thansettling through the bath to form a sludge, there is employed the trap40. Various known commercially available water traps may be employed fortrap 40 in the system shown. A typical water trap which has provedsatisfactory is the bucket type trap which is shown in Figure 5. Suchtrap consists of an upper portion 44 to which is connected the inletpipe 38 from the tank 2 and an outlet pipe 42, part 44 forming a. capfor the bottom cup portion 46 of the trap, to which bottom cup portionit is sealed as by a gasket. Part 44 is provided with a downwardlyextending central hollow stem 48 along which is guided for axialmovement the vertically movable bucket 50. Radially directed struts 52attached to the inner surface of the bucket serve to center the bucketrelatively of the stem and to guide it for travel .therealong. Thebottom of the bucket is provided with an inwardly directed adjustablevalve needie 54 cooperating with the conical opening 56 in the lower endof the hollow stem 48, so that when the bucket is raised the valveneedle closes the passage through the stem and when the bucket islowered such passage, which leads from the interior of the bucket to theoutlet pipe 42, is open. It will be apparent that when the uplift on thebucket from water on the outside thereof exceeds the weight of thebucket and the materiaLwithin it, the bucket will rise and will closethe valve, and that when the weight of the bucket and the materialwithin it exceeds the uplift, the bucket will sink and open the valve.

Condensate from the air, oil, and foam flowing through pipe 38 .will'overflow over the upper edge of the bucket, the water being on thebottom and the oil and foam floating on the top. When suflicient water,oil, and foam have gathered within the bucket so that its weightovercomes the uplift on the bucket, the bucket moves downwardly, openingthe valve in the hollow stem and allowing first the water in the bucketand then the oil and foam to be forced by the air pressure within tank 2and consequently in pipe 38, out the stem to the exhaust pipe. When thematerial in the bucket has become exhausted sufficiently, however, theuplift on the bucket again exceeds its weight and the valve closes. Suchoperation, continuously repeated, maintains the level 16 0f the liquidbath within the tank constant and insures the constant removal of theoil and foam which forms on top of such bath.

Having thus fully illustrated and described preferred embodiments of theapparatus of my invention, I desire to claim as new the following:

1. Apparatus for washing and cooling compressed gas which comprises aclosed tank having a liquid washing and cooling bath in the bottomthereof, a cylindrical downcomer closed at the top and having an openbottom extending into the bath, means to introduce compressed gas intothe top of the downcomer so that it impinges at a substantial angle on asidewall of the downcomer and travels downwardly thereof, said meanscomprising a nozzle extending through the wall of the downcomer anddirected generally tangentially of the inner wall of the downcomer anddownwardly with respect thereto, whereby the compressed gas afterimpingement on the sidewall travels downwardly in a spiral path throughthe downcomer and then upwardly through the bath outside the downcomer,a perforated plate around the bottom of the downcomer and below the topof the liquid bath in the tank so that the gas is divided into finestreams in its passage through such bath, means to collect the washedgas above the bath in the tank for delivery to a compressed gas usinginstrumentality. and means for cooling the liquid bath to maintain it ata predetermined temperature, whereby the moisture content of the washedgas is adjusted to a point of substantial saturation at the lowesttemperature it subsequently encounters.

2. Apparatus for washing and adjusting the moisture content ofcompressed gas which comprises a closed tank having a liquid washingbath in the bottom thereof, a cylindrical downcomer closed at the topand having an open bottom extending into the bath, means to introducecompressed gas into the top of the downcomer so that it impinges at asubstantial angle on a, sidewall oi the downcomer and travels downwardlythereof, said means comprising a nozzle extending through the wall ofthe downcomer and directed generally tangentially of the inner wall of.the'downcomer and downwardly with respect thereto, whereby thecompressed gas after impingement on the sidewall travels downwardly in aspiral path through the downcomer and then upwardly through the bathoutside the downcomer, a perforated plate around the bottom of thedowncomer and below the top of the liquid bath in the tank so that thegas is divided into fine streams in its passage through such bath, meansto collect the washed gas above the bath in the tank for delivery to acompressed gas using instrumentality, and means for cooling the liquidbath to maintain it at a predetermined temperature, whereby the moisturecontent ofthe washed gas is adjusted to a point of substantialsaturation at the lowest temperature it subsequently encounters, andmeans to maintain the level of the liquid bath in the tank substantiallyconstant and to remove oil and foam from the top of such bath.

3. In the combination of a gas compressor and a compressed gas mainleading therefrom, the improvement which comprises a device interposedin the line between the compressor and the gas main for washing andadjusting the moisture content of the compressed gas, said devicecomprising a closed tank having a liquid washing and cooling bath in thebottom thereof, a cylindrical downcomer closed at the top and having anopen bottom extending into the bath, means to introduce compressed gasinto the top of the downcomer so that it impinges at a substantial angleon a sidewall of the downcomer and travels downwardly thereof, saidmeans comprising a nozzle extending through the wall of the downcomerand directed generally tangentially of the inner wall of the downcomerand downwardly with respect thereto, whereby the compressed gas afterimpingement on the sidewall travels downwardly in a spiral path throughthe downcomer and then upwardly through the bath outside the downcomer,a perforated plate around the bottom of the downcomer and below the topof the liquid bath in the tank so that the gas is divided into finestreams in its passage through such bath, means to collect the washedgas above the bath in the tank for delivery to a compressed gas usinginstrumentality, and means for cooling the liquid bath to maintain it ata predetermined temperature, whereby the moisture content of the washedgas is adjusted to a point of substantial saturation at the lowesttemperature it subsequently encounters.

MARTIN CULKOSKY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

